Technical Field
Embodiments of the present disclosure are directed to leadframe strips and leadless packages, as well as methods of manufacturing leadframe strips and assembling leadless packages.
Description of the Related Art
Leadless (or no lead) packages are often utilized in applications in which small sized packages are desired. In general, flat leadless packages provide a near chip scale encapsulated package that includes a planar leadframe. Lands (also referred to as leads) located on a bottom surface of the package and, in many cases, side surfaces of the package provide electrical connection to a substrate, such as a printed circuit board (PCB). The packages are mounted directly on the surface of the PCB using surface mount technology (SMT).
Although SMT allows for smaller packages, it also creates some disadvantages. In particular, the solder joints between the package and the PCB can be weakened due to the PCB and the package having different coefficients of thermal expansions (CTE). Thus, the reliability of the package may, in some cases, depend on the integrity of the solder joints.
As packages reduce in size, the available space for solder joints is further limited. Thus, strong solder bonds between the lands of the package and the pads of the board are desired.